Puzzled by code in Item menu

Can anyone explain how the following works please:

Item Card/Item/Item Availability by: /Location
(Form 515)
RunFormLink : No.=FIELD(No.), etc
The form is based on the Location table. (there is no “No.”).

I have created a copy of Form 515 to show the In Transit locations and wanted to add it to the menu but could not see how the above RunFormLink is achieved.
It is not possible to use the same code when looking up my new form. I am very puzzled.

TIA,
Colin
[*-)]

The form that is called from the Item Card is Form 492 Item Availability By Location. Form 515 is it’s subform.

Form 492 is based on Item table, which of course has a “No.” field, and is why the link works.

You will also need to create a copy of Form 492, which has your copy of Form 515 as it’s subform.

Ahhh, of course, I must have been a bit tired by the time I lost the plot.

Many thanks for the speedy reply,

Colin